Nursing Field Notes / Cardio · Pathophysiology Course

DVT 🩸

Deep Vein Thrombosis — a CLOT in a deep vein · plus Raynaud's & Buerger's

NG-223 CARDIO ADHD-friendly visual edition

A clot in a deep vein is not dangerous where it sits — it is dangerous where it GOES. Blood from a leg vein travels to the right heart and straight into the lungs. That is why the calf you find swollen today is a pulmonary embolism tomorrow, and why you never massage or vigorously palpate a calf you suspect of clotting.

📄 Simple Nursing original — opens in Drive →

🐄 COWSCalf pain & cramping · One-sided swelling · Warm & red · SOB + chest pain = PE!

🌀 Virchow's triadStasis · Vessel injury · Hypercoagulability. Every risk factor is one of these three.

🚫 NEVER massageNo rubbing, no vigorous palpation, no Homans' maneuver — you can launch the clot into the lungs.

🧪 WEPTWarfarin → PT/INR → vitamin K · Heparin → aPTT → protamine sulfate.

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WHY CLOTS FORM

STEP 1 · VIRCHOW'S TRIAD

Three conditions make blood clot where it shouldn't. Every risk factor you'll ever be asked about slots into one of them.

🌀 VIRCHOW'S TRIAD — the three-legged stool every DVT stands on

🧠 “SHIP” — Stasis · Hypercoagulability · Injury to the Pipe. Picture the classic exam client: a ship passenger on a long flight (stasis), dehydrated with a cocktail (hypercoagulable), just out of knee surgery (vessel injury). All three legs of the triad in one sentence — that client clots.

⚠️ Risk factors, sorted by which leg of the triad

Triad leg	Who's at risk
🧍 STASIS	Post-op & immobile clients · bed rest · casts and splints · paralysis/stroke · long car rides and flights · prolonged sitting · heart failure · obesity · pregnancy (the uterus compresses pelvic veins)
🩹 INJURY	Orthopedic surgery — especially hip and knee replacement · major trauma and fractures · central lines and IV catheters · smoking
🧬 HYPERCOAG	Cancer (and chemotherapy) · dehydration · pregnancy and postpartum · estrogen therapy / oral contraceptives, especially in a smoker over 35 · inherited thrombophilias · sepsis · previous DVT

The highest-yield combination on the exam: a post-operative orthopedic client who has been in bed and is not yet ambulating. That is all three legs at once.

🧠 “The three biggest words: surgery, cancer, estrogen.” If any of those three appear in a stem with a swollen calf, think DVT before you think anything else.

🫙 Deep vs superficial — why only one of them scares you

Superficial thrombophlebitis — clot in a surface vein. You can see and feel a red, tender, cord-like vein just under the skin. Uncomfortable, usually treated with warm compresses, elevation and anti-inflammatories.
DVT — deep vein thrombosis — clot in a deep vein (calf, popliteal, femoral, iliac). You cannot see it. It sits in a high-volume vein with a straight path to the lungs.
That path is the whole point: leg vein → inferior vena cava → right atrium → right ventricle → pulmonary artery → PE.

🧠 “Superficial you can SEE, deep you must SUSPECT.” The clot you can see is rarely the one that kills. The dangerous one is invisible — which is why risk factors and prevention carry so much weight.

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SIGNS & ESCALATION

STEP 2 · SPOT IT

Four letters for the leg. One line for the lungs. And one thing your hands must never do.

🐄 COWS — the DVT sign set, and the S that changes everything

CALF PAIN & CRAMPING — aching, tightness or a “charley horse” that doesn't ease. Often worse with walking or dorsiflexion, and tender along the vein.

ONE-SIDED SWELLING (unilateral) — this is the money sign. Measure calf circumference at the same marked point on both legs and compare. Two swollen legs points at the heart; one swollen leg points at a vein.

WARM & RED — blood pooling behind the clot makes the skin warm, red/erythematous and shiny-tight. May come with a low-grade fever.

SOB & CHEST PAIN = PE! — the clot has moved. Call the provider / rapid response. This is no longer a leg problem.

Also assess: pain on dorsiflexion, a palpable cord, and skin that looks tight and shiny. Do not chart a DVT “ruled out” on findings alone — many DVTs are silent until the PE.

🧠 “COWS come home to the LUNGS.” Calf pain · One-sided swelling · Warm & red · SOB. The first three are the leg; the S is the emergency. If you can only remember one letter, remember that S stands for STOP EVERYTHING.

🚫 NEVER massage or vigorously palpate a calf you suspect has a clot

Why: the thrombus is only loosely attached. Pressure, kneading or forceful dorsiflexion can dislodge it into the circulation, and a venous clot goes straight to the lungs.
Homans' sign (calf pain on forced dorsiflexion) is no longer used — it is unreliable, it misses most DVTs, and the maneuver itself risks dislodging the clot. Inspect and measure instead.
Do NOT apply SCDs to a leg with a known acute DVT unless the provider specifically orders it. SCDs are a prevention device.
Gentle inspection, gentle circumference measurement, and reporting are the assessment. Diagnosis comes from venous duplex ultrasound.

🧠 “Look, measure, report — don't squeeze.” Your hands can turn a leg problem into a lung emergency. Say it while you're washing your hands before you walk in.

🔬 Confirming it — what actually diagnoses a DVT

Venous duplex ultrasound — the first-line, non-invasive test. Shows the clot and whether the vein compresses.
D-dimer — a fibrin breakdown product. A normal D-dimer helps rule OUT a clot; an elevated one does not rule it IN (it rises with surgery, trauma, infection, pregnancy, cancer).
Wells score — a clinical probability tool that decides whether the client goes straight to ultrasound.
For suspected PE: CT pulmonary angiography is the standard confirming study. ABG may show hypoxemia with a low CO₂ from blowing off carbon dioxide.

🧠 “D-dimer is a smoke detector.” No smoke = probably no fire (good rule-out). Smoke = something is burning, but it might just be the toast. You still need the picture.

🚨 PE — what it looks like when the clot arrives

😮‍💨 SUDDEN shortness of breath — the hallmark. Abrupt, not gradual.
💥 Sharp, pleuritic chest pain — worse on deep breath.
💓 Tachycardia and tachypnea; low SpO₂ despite effort.
😰 Anxiety, restlessness, a sense of impending doom — take this seriously, it is a real early sign of hypoxia.
🩸 Cough, sometimes with blood-streaked sputum (hemoptysis).
📉 Hypotension, cyanosis, syncope = massive PE, obstructive shock.

🧠 “Sudden + Short of breath + Sharp chest pain + Scared = PE.” Four S's. In a post-op client with a swollen calf, those four S's are a PE until proven otherwise.

🚨 PE ESCALATION — priority actions in order

STAY with the client and sit them UP — high Fowler's. It maximizes lung expansion immediately and costs nothing.

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Apply OXYGEN and put on continuous pulse oximetry. Hypoxia is what's killing them right now.

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CALL — provider / rapid response. Use the call light or a colleague so you never leave the client alone.

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Vital signs, cardiac monitor, IV access. Establish or confirm a patent IV — the treatment is going to be intravenous.

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Anticipate: IV heparin, CT pulmonary angiography, ABG, D-dimer, ECG, and — for a massive PE — thrombolytics or embolectomy.

Order matters on the exam: when the client is in front of you, do the things that fix oxygenation first (position + O₂), then get help, then gather data. Don't leave the room to page someone.

🧠 “Sit 'em up, O₂ on, call it in.” Three beats, in that order, every time. Everything else — labs, scans, drugs — happens after the client can breathe.

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TREAT & PREVENT

STEP 3 · STOP THE NEXT ONE

Anticoagulants don't dissolve the clot — they stop it from growing while the body breaks it down. Prevention is where nursing wins.

💊 Anticoagulant comparison — which lab watches which drug

Drug	Route & speed	Monitoring	Nursing key points
Heparin unfractionated	IV drip or SC. Immediate onset — this is the one you start in an emergency.	aPTT (some facilities use anti-Xa). Therapeutic ≈ 1.5–2.5× the control value. Also follow PLATELETS.	Antidote protamine sulfate. Watch for HIT — heparin-induced thrombocytopenia: platelets fall (classically >50% drop) and the client paradoxically clots. Stop the heparin and notify. Never rub SC injection sites.
LMWH enoxaparin, dalteparin	SC, weight-based, more predictable than heparin.	No routine aPTT. Anti-Xa level only in select cases (renal impairment, pregnancy, extremes of weight). Follow platelets and renal function.	Give in the abdomen, about 2 inches from the umbilicus. Do not expel the air bubble, do not aspirate, do not massage the site. Protamine reverses it only partially.
Warfarin	PO. Slow — takes several days for full effect, so it is overlapped (“bridged”) with heparin at the start.	PT / INR. Normal INR ≈ 0.8–1.2; therapeutic for VTE/AF is 2.0–3.0. Above range = bleeding risk; below = clot risk.	Antidote vitamin K (phytonadione); major bleeding also gets FFP or prothrombin complex concentrate. Teach consistent vitamin-K intake (green leafy vegetables) — consistency, not avoidance. Many drug/herbal interactions. Contraindicated in pregnancy.
DOACs apixaban, rivaroxaban, edoxaban (factor Xa) · dabigatran (direct thrombin)	PO, fixed dosing, rapid onset.	No routine coagulation monitoring — no INR. Renal function is checked because clearance depends on it.	Reversal: idarucizumab for dabigatran; andexanet alfa for the factor Xa inhibitors. Keep dabigatran in its original bottle and do not crush or open the capsules. Missing doses matters — the protection wears off fast.
Thrombolytics alteplase	IV, reserved for massive PE or a limb-threatening clot.	Continuous monitoring for bleeding of any kind.	Actually dissolves existing clot — and carries the highest bleeding risk of anything on this page. Contraindicated with active bleeding, recent surgery or trauma, and a history of hemorrhagic stroke.

🧠 “WEPT — Warfarin uses PT, Heparin uses PTT.” Then the antidotes rhyme with their drugs: Protamine protects from heparin, and vitamin K fixes Koumadin. If you can say WEPT and those two antidotes, you own the most tested lab-drug pairing in nursing school.

🩸 Bleeding precautions — the same teaching for every anticoagulant

🪥 Soft toothbrush, electric razor, no flossing with force.
🚽 Report black tarry stools, pink/red urine, coffee-ground emesis, bleeding gums, nosebleeds, unusual bruising, or a headache/confusion after a fall.
💊 No NSAIDs or aspirin unless the provider ordered them; check every OTC and herbal product.
🪪 Wear medical-alert identification and tell every dentist and surgeon.
🩹 Hold pressure longer after venipunctures and injections; avoid IM injections when possible.
🤕 Fall precautions — a head strike on an anticoagulant is an emergency even if the client looks fine.

🧠 “Soft brush, electric razor, no NSAIDs, tell the dentist.” Four sentences that answer almost every anticoagulant teaching question.

✅ PREVENTION — the part nursing owns

🚶 Early ambulation after surgery — the single most effective prevention.
🦵 SCDs / intermittent pneumatic compression and graduated compression (TED) stockings for immobile clients. Check skin under them; make sure they aren't rolled or bunched.
💉 Prophylactic anticoagulation — low-dose SC heparin or LMWH for at-risk hospitalized and post-op clients.
💧 Hydration — dehydrated blood is thick blood.
🦶 Ankle pumps, calf exercises and position changes for anyone on bed rest.
❌ No pillows under the knees, no leg crossing, no prolonged sitting — all of them kink the popliteal vein.

🧠 “Move it, squeeze it, thin it, water it.” Ambulate · SCDs · prophylactic anticoagulant · hydrate. Four verbs = the whole prevention bundle.

🎵 CHANT — living after the clot

🦶C — Calf exercise& isometrics

💧H — Hydrationthin the blood

🚶A — Ambulationkeep moving

🪑N — No long sittingcar · airplane · bed rest

🧦T — TED & SCDsafter the clot is resolved

Two nuances the exam cares about:

Elevate the affected leg to promote venous return and reduce swelling — the same rule as every venous problem. SEE NG-161
About activity during the acute clot: older teaching was strict bed rest to keep the clot from moving. Current practice for most stable clients is early ambulation once therapeutic anticoagulation has been started, because it does not raise PE risk and it reduces pain and swelling. Practice and orders vary — follow the provider's order for your client, and never ambulate a client with a new DVT who has not yet been anticoagulated without checking.
TEDs and SCDs go on the leg for PREVENTION, and on an affected leg only once the clot is resolved or specifically ordered.

🧠 “CHANT it while you walk the halls.” Calf exercise · Hydration · Ambulation · No long sitting · TED & SCDs. Five words, one rhythm — and every one of them is the opposite of stasis.

🕸️ When drugs aren't enough: the IVC filter

What it is: a small mesh basket placed in the inferior vena cava to catch clots traveling from the legs before they reach the lungs.

Who gets one: clients who cannot take anticoagulants (active bleeding, recent neurosurgery) or who keep throwing clots despite therapeutic anticoagulation.

What it does NOT do: it does not dissolve clots and it does not prevent new ones from forming — it is a net, not a treatment.

🧠 “A pool skimmer, not a filter for the water.” It catches what floats by; it doesn't clean the pool. Anticoagulation is still the treatment whenever it's safe.

🎨 Also on this card: Raynaud's vs Buerger's

🤍 RAYNAUD'S · “R = Ring finger”	🖤 BUERGER'S · “B = Black fingers & toes”
Spasm of small arteries in the fingers (and toes), triggered by COLD and STRESS.	Buerger's disease (thromboangiitis obliterans) — inflammation and clotting of small and medium arteries and veins in the hands and feet.
Classic color sequence: WHITE (spasm, no blood) → BLUE (deoxygenated) → RED (blood rushes back). Numbness, tingling, throbbing.	Tissue actually dies: intense pain, claudication of the arch of the foot, cold sensitivity, ulcers, and black gangrenous fingers & toes.
Care: keep warm — gloves, warm environment, warm water; avoid cold, caffeine, nicotine; manage stress. Calcium channel blockers are commonly used vasodilators.	Care: absolute, complete tobacco cessation — this is the treatment. Nothing else works if the client keeps smoking. Protect and inspect the extremities; amputation if gangrene.
Episodic and reversible.	Progressive and destructive. Strongly associated with tobacco use in younger adults.

🧠 “R for Ring finger goes Red-White-Blue like a flag. B for Buerger's goes Black — and B stands for Butts (cigarettes).” One changes color and comes back. The other turns black and doesn't.

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QUICK RECALL

SAY IT OUT LOUD

🐄 COWSCalf pain · One-sided swelling · Warm & red · SOB + chest pain = PE, call now.

🌀 TriadStasis · vessel Injury · Hypercoagulability. Post-op ortho client in bed = all three.

🚫 Hands offNo massage, no vigorous palpation, no Homans'. Look, measure, report.

🧪 WEPTWarfarin → PT/INR 2.0–3.0 → vitamin K · Heparin → aPTT 1.5–2.5× → protamine · DOAC → no routine lab.

🎯 Cover & check — 8 rapid-fire questions

Q1: Name Virchow's triad.

Venous stasis, endothelial/vessel wall injury, and hypercoagulability.

Q2: A post-op client has a warm, red, swollen LEFT calf that is 3 cm larger than the right. What must you NOT do?

Do not massage or vigorously palpate the calf, and do not perform a Homans' maneuver — you could dislodge the clot and cause a PE. Notify the provider; anticipate a venous duplex ultrasound.

Q3: Which lab monitors heparin, and what is its antidote?

aPTT (therapeutic roughly 1.5–2.5 times the control value); antidote is protamine sulfate. Also monitor platelets for heparin-induced thrombocytopenia (HIT).

Q4: Which lab monitors warfarin, what is the therapeutic range for VTE, and what is the antidote?

PT/INR; therapeutic INR 2.0–3.0 for VTE; antidote is vitamin K (phytonadione). Major bleeding may also need FFP or prothrombin complex concentrate.

Q5: A client on a DOAC asks when their INR will be checked. Response?

DOACs (apixaban, rivaroxaban, edoxaban, dabigatran) do not require routine INR or aPTT monitoring — that's a major advantage. Renal function is still monitored. Reversal is idarucizumab for dabigatran and andexanet alfa for the factor Xa inhibitors.

Q6: Your client with a known DVT suddenly becomes short of breath with sharp chest pain and says something is very wrong. First actions?

Stay with the client and sit them up (high Fowler's), apply oxygen, then call the provider/rapid response without leaving the room. Then vitals, continuous pulse ox, cardiac monitor, IV access. Anticipate IV heparin and CT pulmonary angiography; thrombolytics for massive PE.

Q7: List four DVT prevention measures.

Early ambulation (best), SCDs/intermittent pneumatic compression and graduated compression stockings, prophylactic anticoagulation, hydration — plus ankle pumps, position changes, no pillows under the knees and no leg crossing.

Q8: A young adult smoker has painful, cold hands and blackened fingertips. Which disease, and what is the treatment?

Buerger's disease (thromboangiitis obliterans). Complete tobacco cessation IS the treatment — no other therapy works while the client keeps smoking. Contrast with Raynaud's, which is episodic white-to-blue-to-red color change triggered by cold and stress.

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STUDY SHEETS

FROM YOUR SAVED SET

D-dimer, PT/INR and aPTT — which drug each one monitors, the goal ranges, and what a high value means. — swipe it sideways if it is cut off, or tap to open it full size.

Saved study graphics from your own collection. Each one is someone else’s work — check anything clinical against your course materials before you rely on it.